Violence in Haiti could break out once more because a UN peacekeeping force is not working hard enough to ensure rival gangs are disarmed, a new report says.
Gunfire, panic and fear are still prevalent on the streets of Haiti
The Small Arms Survey, a Geneva-based research group, says gangs and militias on the streets are still heavily armed.
An armed uprising forced out President Jean-Bertrand Aristide last year, and many of his armed supporters still control large swathes on countryside.
The report comes after a policeman was beheaded and burned in Haiti's capital.
The man, a private security guard working in Port-au-Prince, was found by colleagues in the St Martin district close to the centre of the city.
It was the fourth decapitation of police officers in the city since September.
Haiti's police force is unpopular among many of the country's armed gangs for allegedly targeting supporters of Mr Aristide, who complain of targeted beatings and executions.
Police have opened fire on two pro-Aristide marches in the recent weeks, killing three protesters.
In its report, the Small Arms Survey warns that if groups are not disarmed, the country's pattern of political change at the point of a gun could continue.
Armed gangs are "consolidating their influence and networks throughout the country", and Haiti's government is accused of failing to secure either legitimacy or authority in the eyes of the country's 8m people.
"Without the permanent demilitarisation of armed groups, humanitarian assistance and development will be continually endangered," the report finds.
"Haiti's vicious cycle will thus continue."
It called for tough action on those caught smuggling weapons into Haiti, and severe punishments for gun crime.
In addition, the report urges extra support for gunmen if and when disarmament finally happens.
A mid-2004 deadline for handing in weapons was widely ignored, the report says.
The UN, which has peacekeepers posted on the island, says its forces have only recently come up to strength.
It is likely to ask for more funding for disarmament programmes when a Security Council delegation visits Haiti in the future.